AIR SEPARATION PROCESS AND APPARATUS FOR THE PRODUCTION OF HIGH PURITY NITROGEN

摘要

A process and apparatus for producing a high purity nitrogen vapor product from the rectification of air within high and low pressure columns operatively associated with one another by a condenser-reboiler. The high pressure column incorporates a sufficient number of theoretical stages to produce a high purity nitrogen vapor which after being condensed by the condenser-reboiler, serves to partially condense a lower purity nitrogen vapor tower overhead produced in the low pressure column through indirect heat exchanger. In such service, the condensed, high purity nitrogen vapor is at least partially vaporized and utilized as a product stream. Since there is no direct heat exchange with the high purity nitrogen produced within the high pressure column and the lower purity nitrogen vapor produced in the low pressure column, the low pressure column can incorporate fewer theoretical stages and therefore can be built at less expense than similar air separation plants of the prior art.